Abstract: The present invention relates to an optical device (1) suitable for transmitting/reflecting electromagnetic radiation in a wavelength range of the electromagnetic spectrum, said device (1) comprising at least: a first coating layer (10) made of a first material, a substrate (50) made of a material that is different from the first material, and surface texturing (60) forming cavities (61) in the device (1); wherein a lower layer (50) disposed directly below the first coating layer (10) is either a second coating layer (20) made of a material that is different from the first material, or the substrate (50); wherein the lower layer (50) has a determined thickness (E50); characterised in that the cavities (61) extend through the coating layer (20) and are sunk into the lower layer (50) through at least part of the thickness (E50).

Abstract: The present invention relates to an optical device (1), suitable for transmitting/reflecting electromagnetic radiation in a wavelength range of the electromagnetic spectrum, said device (1) comprising at least: a substrate (10) made of a first material, a coating layer (20) made of a second material that is different from the first material, and surface texturing (30) forming cavities (31) in the device (1), characterized in that the cavities (31) extend through the coating layer (20) and are partially sunk into the substrate (10).